Glazing for electric heating, its manufacturing method and use

Abstract

The invention relates to an electrically heated glazing 10 comprising a glass sheet 1, an electrically conductive coating 2 disposed on the glass sheet 1, a first removal line 3 in the electrically conductive coating 2 forming a heating area 2', a second removal line 4 having a junction with the first removal line 3 and extending into the heating area 2', first and second busbars 5, 6 at least partially on the heating area 2' adjacent the first removal line 3, and an intersection 7 of the first and second busbars 5, 6 at a junction between the first and second removal lines 3, 4. The invention also relates to a method of manufacturing the glazing, and to the use of the glazing, for example as a vehicle window.

Description

[Technical Field]

[0001] The present invention relates to an electrically heated glazing, a method for its production and its use, for example as a vehicle window. [Background technology]

[0002] Electrically heated glazing having an electrically conductive coating on the glass substrate is well known. Bus bars that supply current to the conductive coating are often located near the edge of the glazing. In vehicle side windows, the bus bars may be along the inside lower edge of the vehicle door or on the side edge adjacent to the door frame.

[0003] German Patent Application Publication No. 102004029164 (Baranski / Pilkington) discloses laminated glass with an electrically conductive coating. Two busbars made of metal strips are covered with an insulating layer. Contact windows are provided in the insulating layer to electrically contact the assigned segments of the electrically conductive coating.

[0004] US Patent Application Publication No. 2016 / 174295 A1 (Klein / Saint-Gobain) discloses a heatable laminated side glass pane with an electrically conductive coating divided into segments by insulating wires. First and second bus bars are formed as strips of conductive foil or fired printing paste.

[0005] German Patent Application No. 102013007381 (Straube / Volkswagen) discloses a transparent window pane with a heatable coating and at least one busbar, which is printed on the coating and comprises an insulating layer printed on a conductive layer.

[0006] There remains a need for alternative glazing for electric heating, particularly those having busbars positioned along at least one edge of the glazing. Summary of the Invention [Problem to be solved by the invention]

[0007] It is an object of the present invention to provide an electrically heated glazing having a desired heat distribution for improved defrosting or defogging during use. Another object is to provide a simple method for manufacturing the electrically heated glazing. [Means for solving the problem]

[0008] In a first aspect, the present invention provides a glazing for electric heating having the features of claim 1.

[0009] The present invention discloses an electrically heated glazing comprising: a glass sheet; an electrically conductive coating disposed on the glass sheet; a first removal line in the electrically conductive coating forming a heating zone; a second removal line having a junction with the first removal line and extending into the heating zone; first and second bus bars at least partially over the heating zone adjacent to the first removal line; and an intersection of the first and second bus bars at the junction between the first and second removal lines.

[0010] The present invention is advantageous because the glazing having the intersection of the first and second busbars improves heat distribution compared to conventional glazing.

[0011] Surprisingly, the crossing of the busbar adjacent to the first removal line allows current to flow along most of the length of the busbar, resulting in uniform heating. Conventional glazing has an insulating layer that covers most of the length of the busbar, so current flows only through the contact window, creating hot spots.

[0012] Glazing according to the present invention, which allows current to flow along most of the length of the busbar, defrosts or defogs more quickly than conventional glazing.

[0013] Sets of heating zones are connected as parallel circuits to the first and second bus bars between adjacent intersections. The parallel circuits can be arranged to achieve the desired heat distribution using fewer components than conventional glazing.

[0014] The result of the present invention is that the glazing meets industry test requirements for defrosting, for example, for vehicle windows.

[0015] Preferably, in use, current flows from the first busbar to the second busbar within the heated coating at least partially around the second removal line.

[0016] Preferably, the conductive coating is a pyrolytically deposited transparent conductive oxide. More preferably, the coating is a fluorine-doped tin oxide deposited at temperatures above 400°C during the float glass manufacturing process. Advantageously, the pyrolytically deposited coating is a hard coating, as opposed to the soft coatings formed by sputtering. Alternatively, the coating is a sputtered coating with two, three, or four layers of silver.

[0017] Preferably, the first removal line in the conductive coating insulates the heated area from the unheated area of ​​the conductive coating. The first removal line is advantageous because it eliminates the need to remove large areas of the conductive coating. Preferably, the first removal line is a plurality of removal lines. Preferably, the removal lines in the plurality of removal lines are parallel to each other and spaced apart from each other.

[0018] Preferably, the second removal line extends to edges of the conductive coating adjacent the first and second bus bars in the unheated region to prevent electrical shorting between the bus bars.

[0019] Preferably, the second removal line comprises a removal area at the intersection. The removal area is advantageous as it provides an insulating area and reduces the risk of electrical shorts.

[0020] Preferably, the first and second bus bars comprise a conductive ink, which is advantageous because the conductive ink can be printed directly onto the conductive coating using methods known in the art.

[0021] Preferably, an insulating layer is located between the first and second busbars at the intersection. The insulating layer at the intersection requires less insulating material than conventional glazing, which has insulating material except for the contact window, thereby saving costs. In an advantageous embodiment, the insulating layer is a non-conductive ink, preferably printed on the first busbar before printing the second busbar.

[0022] Preferably, the glazing comprises a first zone boundary having a junction with the first removal line, the first zone boundary extending further into the heating zone than the second removal line, and the intersection of the first busbar and the second busbar is located at the junction between the first removal line and the first zone boundary.

[0023] The zone boundary restricts current flow within the zone and controls heat distribution within the heated region. In an advantageous embodiment, the zone boundary is an ablation line, preferably formed by laser ablation of the conductive coating. Preferably, the zone boundary extends from a first ablation line to an opposite edge of the conductive coating. Preferably, the zone boundary extends from the first ablation line in the unheated region to an edge of the conductive coating.

[0024] Preferably, the glazing comprises a second zone boundary. Advantageously, the first and second zone boundaries provide a zone region through which current flows between adjacent sections of the first and second busbars on either side of the intersection. Preferably, in use, the power density in the heated region of the conductive coating between the first and second zone boundaries is between 200 and 1000 W / m 2 , more preferably 300 to 600 W / m 2Power densities in these ranges are desirable for effective defrosting or defogging of vehicle glazing, for example.

[0025] In a second aspect, the present invention provides a method for manufacturing a glazing comprising the steps as claimed in claim 10.

[0026] The present invention provides a method for manufacturing glazing according to the present invention, the method comprising the steps of: providing a glass sheet; disposing a conductive coating on the glass sheet; providing a first removal line in the conductive coating; forming a heating zone; configuring a second removal line having a junction with the first removal line and extending into the heating zone; disposing first and second bus bars at least partially on the heating zone adjacent to the first removal line; and configuring an intersection of the first and second bus bars at the junction between the first and second removal lines.

[0027] Preferably, the method of manufacturing glazing further comprises pyrolytically depositing a conductive coating, preferably during manufacture of the glass sheet. Preferably, the coating is deposited by chemical vapor deposition (CVD). Pyrolytically depositing a conductive coating during manufacture of the glass sheet provides an alternative to sputtering and provides a more durable coating during use.

[0028] Preferably, the method for manufacturing the glazing further comprises the step of forming the removal line by laser ablation of the heated coating. The step of laser ablation provides an alternative to mechanical polishing. Preferably, the first removal line and / or the second removal line are formed by laser ablation of the heated coating.

[0029] Preferably, the method for manufacturing the glazing further comprises printing the first bus bar using a conductive ink. The printing step provides an alternative to stamping a metal foil. Similarly, the second bus bar can be applied after the first bus bar by printing using a conductive ink.

[0030] Preferably, the method for manufacturing the glazing further comprises the step of printing an insulating layer using a non-conductive ink between the steps of printing the first and second bus bars using a conductive ink. The step of printing an insulating layer using a non-conductive ink provides an alternative to placing adhesive patches.

[0031] In a third aspect, the present invention provides the use of a glazing according to the invention as a heated window in a land, sea or air vehicle, for example as a windscreen, rear window, side window or roof window in a car. The present invention may also be used as an electric heater for buildings, for example mounted in the walls or windows of a refrigerator door or in street installations.

[0032] The present invention is further disclosed by the following non-limiting figures, non-limiting examples and comparative examples. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is an embodiment of the present invention having crossover. [Figure 2] FIG. 2 is a cross-sectional view of the embodiment of FIG. [Figure 3] 1 is an embodiment of the present invention having a removed region. [Figure 4] FIG. 4 is a cross-sectional view of the embodiment of FIG. [Figure 5] 1 is an embodiment of the present invention having an insulating layer. [Figure 6] FIG. 6 is a cross-sectional view of the embodiment of FIG. 5. [Figure 7] 1 is an embodiment of the present invention having zone boundaries. [Figure 8]FIG. 8 is a cross-sectional view of the embodiment of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0034] FIG. 1 discloses an electric heating glazing 10 according to the invention, comprising a glass sheet 1 and an electrically conductive coating 2 disposed on a major surface of the glass sheet 1 .

[0035] The glass sheet is preferably soda-lime-silica glass produced using the float process. The glass thickness is preferably in the range of 2 to 12 mm. The glass sheet may be tempered glass with a surface stress of more than 65 MPa, heat-strengthened glass with a surface stress of 40 to 55 MPa, semi-tempered glass with a surface stress of 20 to 25 MPa, or annealed glass.

[0036] The glazing can be monolithic, comprising only one sheet of glass. Monolithic glazing has the advantage of saving weight compared to laminated glass.

[0037] The glazing can be laminated glass comprising first and second glass sheets with a ply of interlayer material, preferably polyvinyl butyral (PVB), between them. Preferably, the laminated glass has a conductive coating and busbar adjacent to the ply of interlayer material. This is advantageous for movable door windows because it reduces wear on the seal between the window and the door frame. Laminated glass also offers safety advantages.

[0038] The conductive coating 2 may comprise a transparent conductive oxide such as tin oxide or fluorine-doped tin oxide that is deposited on the glass sheet 1 during the glass manufacturing process.

[0039] A first removal line 3 is provided in the conductive coating 2, forming the heated area 2'. In one embodiment of the present invention, the first removal line 3 is the entire area of ​​the conductive coating 2 adjacent the edge of the glazing 10. In an advantageous embodiment, the first removal line 3 is a laser removal line in the conductive coating, insulating the heated and unheated areas. The unheated area is adjacent the edge of the glazing 10. In the case of vehicle side glazing, the unheated area and a portion of the heated area 2' containing the first and second busbars 5, 6 are at the bottom of the glass and hidden from view inside the vehicle door. When the side glazing is in the closed position, the remainder of the heated area 2' is visible.

[0040] A second removal line 4 extends into the heated region 2', having a junction with the first removal line 3. If an unheated region of the conductive coating 2 is provided, the second removal line 4 also extends to the entire area of ​​the conductive coating 2 adjacent the edge of the glazing 10 in the unheated region.

[0041] The first and second bus bars 5, 6 are spaced apart from one another and are in electrical contact with at least a portion of the heated area 2' to form a heated coating 8.

[0042] In an advantageous embodiment, the heated coating 8 is partially bounded at its lower edge by the inner edges of the first and second bus bars 5, 6. The first and second bus bars 5, 6 may have any shape, for example, straight, arcuate, or multi-section, each section being straight or arcuate. The first and second bus bars 5, 6 may comprise any electrically conductive material, for example, silver.

[0043] The heated coating 8 may for example be partially bounded on the left and right sides by the left and right sides of the conductive coating 2 .

[0044] Removal of the conductive coating material can be accomplished by laser ablation, mechanical abrasion, or other methods known in the art. The width of the uncoated line typically ranges from 10 μm to 5 mm.

[0045] Figure 2 is a cross-sectional view of the embodiment of Figure 1 taken along line AA. A first busbar 5 extends from the junction between the first and second removal lines 3, 4 to the left within the heated region 2'. A second busbar 6 extends from the junction between the first and second removal lines 3, 4 to the right within the heated region 2'. The intersection 7 of the busbars is shown as, but is not limited to, two wedges.

[0046] 3 discloses an embodiment of the present invention having a removed region 4'. The width, length, and shape of the removed region 4' are not limited. Although the shape of the removed region 4' is shown as a rectangle, it may be any shape formed by a straight line, a circular arc, or a combination of a straight line and a circular arc.

[0047] Figure 4 is a cross-sectional view of the embodiment of Figure 3 taken along line AA. Removal areas 4' may be formed by laser ablation or mechanical abrasion, similar to second removal lines 4. Removal areas 4' may be completely removed as shown, or may include a pattern of removal lines, such as a grid.

[0048] 5 discloses an embodiment of the present invention having an insulating layer 9. The width, length, and shape of the insulating layer 9 are not limited, except that the insulating layer must completely insulate the overlap between the first and second bus bars 5, 6 to avoid short circuits.

[0049] Figure 6 is a cross-section of the embodiment of Figure 5 along line AA. The insulating layer 9 is preferably printed using a non-conductive ink or provided as an adhesive patch.

[0050] 7 discloses an embodiment of the present invention having first and second zone boundaries 11, 12 and two zone regions. The first zone region is on the left and is the heating coating 8 bounded by the left edge of the conductive coating 2 and the first zone boundary 11. The second zone region is on the right of the first zone region and is the heating coating 8 bounded by the left edge of the conductive coating 2 and the first zone boundary 11. The second zone region is also bounded by the top edge of the conductive coating 2, the first and second busbars 5, 6, and three removal regions 4′.

[0051] Figure 8 is a cross-sectional view of the embodiment of Figure 7 taken along line AA. In this embodiment, each of the four intersections has a removal area 4' and an insulating layer 9. Advantageously, each intersection has a positional tolerance that accommodates positional variations in the manner in which the first and second busbars are applied relative to the second removal line and the first and second zone boundaries. [Explanation of symbols]

[0052] 1 glass sheet 2. Conductive coating 2' heating area 3 First Removal Line 4 Second Removal Line 4' removed area 5 First bus bar 6 Second busbar 7 Intersection 8. Heated Coating 9 Insulating layer 10 Glazing 11 First Zone Boundary 12 Second Zone Boundary

Claims

1. An electric heating glazing 10, 1. A glass sheet; a conductive coating 2 disposed on said glass sheet 1; a first removal line 3 in said conductive coating 2 forming a heating area 2'; a second removal line 4 having a junction with the first removal line 3 and extending into the heating area 2'; first and second bus bars 5, 6 at least partially lying on the heating area 2' adjacent to the first removal line 3; an intersection 7 of the first and second busbars 5, 6 at said junction between the first and second removal lines 3, 4; Equipped with Here, the first and second removal lines 3, 4 are lines from which the material of the conductive coating 2 has been removed, in an electric heating glazing 10.

2. 2. The glazing (10) of claim 1, wherein, in use, an electric current flows within a heated coating (8) from the first busbar (5) to the second busbar (6) at least partially around the second removal line (4).

3. 3. The glazing (10) according to claim 1 or 2, wherein the conductive coating (2) is a pyrolytically deposited transparent conductive oxide.

4. The glazing (10) according to any one of claims 1 to 3, wherein the first removal line (3) insulates the heated area (2') from the non-heated area of ​​the conductive coating (2).

5. The glazing (10) according to any one of claims 1 to 4, wherein the second removal line (4) comprises a removal area (4') at an intersection (7).

6. 6. A glazing (10) according to any one of the preceding claims, wherein the first and second busbars (5, 6) comprise a conductive ink.

7. 7. A glazing (10) according to any one of the preceding claims, further comprising an insulating layer (9) between the first and second busbars (5, 6) at the intersection (7).

8. 8. The glazing 10 of claim 1, further comprising a first zone boundary 11 having a point of contact with the first removal line 3 and extending further into the heating region 2′ than the second removal line 4, wherein the intersection 7 of the first and second busbars 5, 6 is located at the point of contact between the first removal line 3 and the first zone boundary 11.

9. 9. A glazing (10) according to any one of claims 1 to 8, further comprising a second zone boundary (12), wherein in use the power density in the heating zone (2') between the first and second zone boundaries (11, 12) is between 200 and 1,000 W / m2.

10. 10. A method for producing an electric heating glazing 10 according to claim 1, comprising the steps of: Providing a glass sheet 1; disposing a conductive coating 2 on said glass sheet 1; providing a first removal line 3 in the conductive coating 2 to form a heating area 2'; constructing a second removal line (4) having a junction with the first removal line (3) and extending into the heating area (2'); - positioning first and second busbars 5, 6 at least partially on said heated area 2' adjacent said first removal line 3; - configuring an intersection 7 of the first and second busbars 5, 6 at the junction between the first and second removal lines 3, 4; 2. A method for manufacturing the electric heating glazing (10) of claim 1, comprising:

11. 11. A method for producing a glazing (10) according to claim 10, further comprising the step of pyrolytically depositing the conductive coating (2) during the manufacture of the glass sheet (1).

12. 12. A method for manufacturing a glazing (10) according to claim 10 or 11, further comprising the step of forming the first removal line (3) and / or the second removal line (4) by laser removal of the conductive coating (2).

13. 13. A method for manufacturing a glazing (10) according to any one of claims 10 to 12, further comprising the step of printing the first busbar (5) with a conductive ink.

14. 14. A method for manufacturing a glazing (10) according to any one of claims 10 to 13, further comprising the step of printing an insulating layer (9) with a non-conductive ink between the steps of printing the first busbar (5) and the second busbar (6) with a conductive ink.

15. 10. Use of the glass 10 according to claim 1 as a windscreen, rear window, side window or roof window of a motor vehicle, or as a heater or refrigerator door in a building or a window in a street installation.

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